Question

Curved surface area of a cone is 308 cm2 and its slant height is 14 cm. Find (i) radius of the base and (ii) total surface area of the cone.

Answer 1

Solution:-
Given : Curved surface area of the cone = 308 sq cm and Slant height or l = 14 cm.
Curved surface area of the cone = πrl
308 = 22/7*r*14
r= (308*7)/(22*14)
r = 7 cm
Total surface area of the cone = πr(r+l)
= (22/7*7)(7+14)
= 22*21
Total surface area of the cone = 462 sq cm
So, the radius of the base of the cone is 7 cm and the total surface area of the cone is 462 sq cm.
Answer.

Answer 2

given l= 14cm
curved surface area =308cm^2
πrl=308
22/7×r×14 =308
44/r= 308
r=308/44
i) r =7cm
ii) total surface area = πrl(r+l)
=22/7×7(7+14)
=22×21
=462